For the purpose of richening nutrient, it is conventionally known to apply liquid coating material containing effective component to the surfaces of grains. In the case of coating the grain surfaces with slightly soluble or insoluble vegetable fiber such as rice bran or wheat bran which has been known as effective component, binder is used to apply powder of the vegetable fiber to the grain surfaces. For example, reference 1 discloses that water containing binder, rice bran, and grains are stirred within a drum to apply the rice bran to the grain surfaces.
Reference 2 discloses a method for manufacturing coated rice wherein powdered material is continuously applied to the grains. Although the continuous application of the powdered to the grains is possible, the grains are coated with release agent in a process subsequent to the application of powdered material to the grains, in order to prevent the grains from being adhered to one another. However, reference 2 does not disclose any step for drying the grains after coating, and therefore, any possibility of continuously producing coated rice is uncertain.
Reference 3 discloses the use of a vibration-type drying apparatus to continuously carry out the drying. Reference 4 discloses disk conveyor-type drying apparatus. In the vibration-type drying apparatus, the vibration can facilitate adhering grains to one another and in the disk conveyor-type drying apparatus, it is difficult to make the grain surfaces smoother. In addition, since the disk conveyor has to ensure a space required to place the grains thereon, any compactness of the apparatus can not be expected.
For this reason, the foregoing, it is desired to provide a compact coating apparatus capable of applying uniformly powdered material consisting of slightly soluble or insoluble effective component, such as rice bran, wheat bran or the like, to grains, continuously carrying out drying of the grains after the application of the powdered material to prevent the grains from being adhering to one another, and making the grain surfaces smoother after application of the powdered material to the grains.    Reference 1: Japanese Patent Publication 2005-95070    Reference 2: Japanese Patent Publication 2006-304690    Reference 3: Japanese Patent Publication Heisei 8-322486    Reference 4: Japanese Patent Publication 2007-110971